// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_MESSAGE_CENTER_POPUP_TIMER_H_
#define UI_MESSAGE_CENTER_POPUP_TIMER_H_

#include <string>

#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/time/time.h"
#include "base/timer/timer.h"

namespace message_center {

// A class that manages timeout behavior for notification popups.  One instance
// is created per notification popup.
class PopupTimer {
public:
    // Host the callback for each timer when its time is up.
    class Delegate {
    public:
        virtual void TimerFinished(const std::string& id) = 0;
    };

    // Accepts a notification ID, time until callback, and a reference to the
    // delegate which will be called back.  The reference is a weak pointer so
    // that timers never cause a callback on a destructed object.
    PopupTimer(const std::string& id,
        base::TimeDelta timeout,
        base::WeakPtr<Delegate> delegate);
    ~PopupTimer();

    // Starts running the timer.  Barring a Pause or Reset call, the timer will
    // call back to |delegate| after |timeout| seconds.
    void Start();

    // Stops the timer, and retains the amount of time that has passed so that on
    // subsequent calls to Start the timer will continue where it left off.
    void Pause();

    // Stops the timer, and resets the amount of time that has passed so that
    // calling Start results in a timeout equal to the initial timeout setting.
    void Reset();

    base::TimeDelta get_timeout() const { return timeout_; }

private:
    // Notification ID for which this timer applies.
    const std::string id_;

    // Total time that should pass while active before calling TimerFinished.
    base::TimeDelta timeout_;

    // If paused, the amount of time that passed before pause.
    base::TimeDelta passed_;

    // The time that the timer was last started.
    base::Time start_time_;

    // Callback recipient.
    base::WeakPtr<Delegate> timer_delegate_;

    // The actual timer.
    scoped_ptr<base::OneShotTimer> timer_;

    DISALLOW_COPY_AND_ASSIGN(PopupTimer);
};

} // namespace message_center

#endif // UI_MESSAGE_CENTER_POPUP_TIMER_H_
